A ladder is most often used to reach high locations on buildings and other structures and particularly used to gain access to the roof of such structures. The typical ladder is made up of longitudinal rails with rungs disposed therebetween along the longitudinal length of the rails. Two or more ladder sections can be combined to form an extension ladder. An extension ladder enables a person to reach higher areas of a structure with a ladder that can be extended to nearly twice its length.
Thus, because of a ladder's design, the upper end is inherently prone to slipping and toppling over from even the slightest movement by one positioned on the upper part of the ladder. This is especially true when the angle of inclination is closer to vertical.
In addition, using a ladder to access a roof poses other problems. In order to gain access to the roof of a relatively low lying structure, a ladder is positioned on a side of the structure, usually with the top of the ladder adjacent to the roof. Typically, and in accordance with governmental safety regulations, the upper most part of the ladder must extend above the edge of the roof so that a person can adequately step onto the roof. Specifically, the Occupational Safety and Health Administration in 29 C.F.R. .sctn. 1926.1053(b)(1) specifies that where portable ladders are used for access to an upper landing surface, the ladder side rails shall extend at least three feet above the upper landing surface to which the ladder is used to gain access.
In order for a person to access the roof when exiting a typical ladder, he must step around one of the side rails of the ladder. This situation promotes the dangerous possibility of the ladder being pushed off the building by the force of a person's foot as he steps from the ladder. In addition, the safety of the person can be compromised at that moment, since the person may rely on the ladder rails to hang onto while stepping from the ladder onto the roof.
These conditions also occur when a person is merely using the ladder to reach high locations. For example, when using a ladder on a typical residential house, the upper most part of the ladder is typically leaned against the outer edge of the gutter. The contact area between the gutter and the ladder is extremely small since it is only the edge of the gutter that contacts the ladder rails. Due to the low coefficient of friction for the typically smooth metal gutter, especially at an edge, a very dangerous condition is created. Any slight lateral force can cause the ladder to slide across the gutter and even topple over. This condition is not unique to gutters on residential homes. It can occur in any circumstance where the ladder is leaned against a metal edge or other material with a low coefficient of friction.